The present invention relates to new compressed tablets for disintegration in the colon, as well as a process for preparing same.
In the present specification and claims the term "compressed tablets for disintegration in the colon" is meant to connote compressed tablets of which the center containing the active agent is substantially disintegrated specifically at the level of the colon.
From the French Patent No. 1,591,602 there are known pharmaceutical compositions in unit dosage forms for oral administration, in which the active agents remain substantially protected from the digestive juices of the stomach and of the small intestine, and are practically entirely released in the colon. In these pharmaceutical dosage forms the pharmacologically active agents are finely divided and coated by a resin.
These dosage forms possess a certain number of disadvantages. The duration of the gastro-intestinal passage varies considerably from one individual to another and depending on the size of the meals this individual has consumed it can range from about twelve hours to more than twenty-four hours. Given that the degree of dissolution of resin covering the active agents is proportional to the passage time, release of the pharmacologically active ingredients exactly at the level of the colon is rather uncertain. In addition, it is difficult to coat the active agents homogeneously.
Attempts have, therefore, been made to find a technique other than simple dissolution in order to achieve complete specificity of release of the active agents at the level of the colon.